Valve structure



Nov. 26, 1957 G. P. 'GREENAMYER 2,814,447

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l' ff. guai l (ttorneg United States Patent VALVE STRUCTURE George P.Greenamyer, Monrovia, Calif., assignor to General Controls Co.,Glendale,r Calif., a corporation of California Application May 20,1955', Serial No. 509,856

The portion of the term of the patent subsequent to April 10, 1973 hasbeen disclaimed or dedicated to the public 13 Claims. (Cl. 236-48) Thisinvention relates to valve structures of the type more particularlyadapted for controlling supply of fuel gas to heating equipment andwhich includes thermostatically operated valve means for maintaining aneven temperature in a space, such as a room or oven, heated by theequipment.

The invention of the present application has substantially the sameobjects in View as those of the inventions disclosed in the copendingapplications of Richard D. Grayson, Serial No. 476,633, led December 21,1954, now Patent No. 2,766,773, granted October 16, 1956, and Serial No.483,683, filed January 24, 1955, now Patent No. 2,741,266, granted April10, 1956, and constitutes, in some respects, an improvement thereon.

A general object of this invention is to provide a valve structure whichincludes a pair of valves arranged in series to control ilow of gas fromthe inlet to the outlet of the structure and means, including meansmovable gradually in response to variation of the space temperature, foroperating the valves sequentially and so as to control flow of gas tothe equipment burner in the following manner:

When the space temperature is considerably below that for which thetemperature responsive means is set the valves are fully open so thatgas then passes through thestructure at a rate such that a high-tirecondition of the burner is produced. With rise of space temperature thevalve adjacent the outlet of the structure is closed gradually tomodulate the flow, and when it is fully closed gas passes by way of thestill-open inlet valve through a restricted passage, luy-passing theoutlet valve, to produce a predetermined low-fire condition of theburner. With continued rise of spacer temperature, if such should occurdespite the low-fire, the inlet valve is closed so that supply` of gasto the burner is shut 01T. With subsequent fall oi space temperature,due to the absence of heating, the outlet valve is opened, at leastpartially, before the inlet valve is opened, so that when the inletvalve is subsequently opened gas can pass at relatively high rate(Sullicient to ensure lighting of the burner by the usual means) by wayof the outlet valve as well as through the restricted passage.

For full understanding of the invention, and further appreciation of itsobjects and advantages, reference is to be had to the following detaileddescription and accompanying drawing, and to the appended claims.

In the drawing:

Figure l is a more-or-less diagrammatic sectional View of a valvestructure embodying this invention; and

Figures 2, 3 and 4 are views of a part of the structure of Fig. lshowing the valves in dilterent positions assumed in operation.

Referring first more particularly to Fig. l, the numerals 11 and 12'indicate the two interconnected sections of a valve casing having aninlet 13, an outlet 14, and an elongated generally-cylindrical cavitytherebetween which is divided by a pair of transverse partitions 15 andYICC 2 16 to form an inlet compartment 17, an outlet compartment 18, anda chamber 19 between the partitions. In the bottom wall of chamber 19 isa right-angled passage 20 which leads, through both sections of thecasing, to the outlet 14. Passage 20 is adjustably restricted by arotatable valve plug 21.

The partitions 1-5 and 16 have aligned ports therethrough, around whichports the material of the partitions is raised to provide annularknife-edged valve seats 22 and 23. Cooperable with seat 22 is an inletclosure 24 (provided with a facing 24 of rubber-like material) having astem 25 guidingly receivedin an opening through the hub 26 of a spiderin the inlet port, the closure being biased toward seated position bythe force of a light spring 27 compressed between it and an access cap28 which forms the end wall of compartment 17.

Cooperable with seat 23 is an outlet closure 29 mounted on a member 30which is reciprocable in an opening through the hub 31 of a spider inthe outlet port. The outlet closure 29 has a central opening freelyiitting the reduced left-hand portion of member 30 and, as shown in Fig.l, is held in engagement with a shoulder on the member by the force of arelatively stiff spring 32 compressed between the closure and the headedleft extremityl of the member. This arrangement constitutes a yieldable,or biased lost-motion, connection between the outlet closure and member30.

Between member 3d and the inlet closure 24' is a lostmotion connectionof the snap-action type which comprises a llat arm 33 which is pivotedat its upper end on a pin 34 fixed to the casing, this arm beingrockable between alternate positions determined by a pair of stopelements 35 and 36, the stop element 35 being of the adjustableeccentric type. The lower extremity of arm 33 cooperates with the tip ofan adjusting screw 25l in the stem portion 25 of closure 24.

For moving arm 33 abruptly between its stopped positions there is abowed spring 37, of at metal, which bears at its top in a notch in theleft edge of arm 33, and at its bottom in a notch in an off-set portionof another flat arm 38 behind arm 33 and conveniently pivoted on pin 34.The left edge of arm 38 is maintained continuously in engagement withthe tip of an adjusting screw 30 in member 30 by the force of a spring39, compressed between the casing and the lower end of arm 38, so thatthe position of the bottom of spring 37 is determined by the position ofmember 30. When arm 38 is rocked in either direction slightly beyond aposi'- tion wherein the opposite ends of the bowed spring 37 are alignedwith pivot 34 the arm 33 is snapped to its alternate stopped positionand held in that position by the bowed spring.

For operating the member 30 there is shown, by way of example, a luidpressure motor, preferably of the liquid-filled type, which comprises aneXpansible-contractible bellows 50 disposed in a recess in the outerwall of casing-section 12, and an interconnected thermal bulb 51 which,it is to be assumed, is arranged to respond to the temperature of aspace heated by appara-tus supplied with fuel gas by way of the valvestructure.

Bellows 50 is backed by a temperature-setting dialscrew 52 and has `astem 53 which projects, sealingly, into,

the outlet compartment 18 and there engages a pivoted lever 54 which inturn engages another lever 55 whose free end bears against the left endof member 30. Member 30, levers 54, 55 and bellows-stem 53 aremaintained continuously in interengagement by the force of spring 39acting on the member through arm 38. The movement-amplifying leverarrangement is desirable in connection with control of temperaturewithin a narrow range, .as in a room, but is not required when thetemperature range is relatively wide, as in an oven.

In Fig. l the parts are shown in positions corresponding to lowtemperature at the thermal bulb, bellows 50 being so contracted that theoutlet closure 29 is in wideopen position under the force of spring 39acting through lever 38 and member 30, the inlet closure 24 alsobeingfully-open since the bottom of the `bowed spring 37 is at the leftof its dead-center position and the force of this spring is thuseffective to hold arm 33 against stop element 36 and the inlet closureunseated against the light force of spring 27. It is to be observed thatif the cap 28 were arranged to limit opening of the inlet closure to theposition shown in Fig. l, the stop element 36 could be eliminated. Withclosures 24 and 29 in fully open position gas can pass (as indicated bythe flow-arrows) around the closures, and through the restricted passage20, at a rate sufficient to produce a high-fire condition of the burner.

With rise of temperature .at the thermal bulb and correspondingexpansion of the bellows, the member 30 is moved gradually to the rightso that the outlet closure 29 is brought closer to its seat 23 tothrottle the flow of gas. If the bulb temperature continues to rise theoutlet closure is brought into engagement with its seat as shown in Fig.2. It will be observed that spring 37 has not yet reached itsdead-center position so that it is still effective to maintain the inletclosure unseated, and gas therefore passes to the burner by way of therestricted passage whose ow capacity is adjusted by plug 21 so that apredetermined low-fire condition of the burner is produced.

Under cold-weather conditions the operation is usually such that theoutlet closure modulates between high-fire and low-tire positions. Butif the bulb temperature continues to rise after the parts have reachedtheir low-fire positions, the resultant farther expansion of the bellowseffects movement of member 30 relative to the outlet closure,compressing spring 32, until arm 38 reaches a position wherein thebottom of spring 37 is just beyond its dead-center position (theposition in which the ends of this spring are aligned with the pivot pin34) so that under the force of spring 37 the arm 33 is snapped to itsalternate position in engagement with stop 35, in which position thelower extremity of this arm is free from engagement by the stem of theinlet closure 24 so that the same seats under the force of spring 27 andiiow of gas to the burner is shut off. The parts are shown inthiscondition in Fig. 3. To extend the range of low-fire operation of theburner the stop 36 is positioned so that snap-over` of arm 33 `occursonly after member 30 has moved through a substantial distance beyond thepoint at which the outlet closure seated.

When, due to the absence of heating, the member moves toward the left inresponse to cooling of the thermal bulb and contraction of the bellows,it engages the outlet closure and unseats it before arm 38 reaches aposition corresponding to the dead-center position of spring 37 (thiscondition of the parts being shown in Fig. 4) so that when the inletclosure is finally snapped-open gas can pass around the outlet closureand through passage 270 in an amount suiiicient to ensure promptlighting of the burner by the usual pilot-burner flame or other ignitingmeans. The distance from its seat at which the outlet closure will be atthe instant the inlet closure opens is determined `by the adjustedposition of stop element 35. To avoid excessive noise at the burner whenthe gas is lighted, the stop is preferably adjusted so that the rate ofinitial flow of gas is only just suiiicient to ensure proper lighting.

While various forms of snap-action means can be employed according tothis invention, snap-action means of the type (such as that shown)having stable equilibrium in both of its snapped positions is preferredsince it can be adjusted more readily and accurately to determine (l)the extent of movement of member 30 after the outlet closure is seatedand before the inlet closure is snapped closed, and (2) the extent ofopening of the outlet closure before the inlet closure is reopened.

The specific embodiment of my invention herein shown and described isobviously susceptible of modication without departing from the spirit ofthe invention, and I intend therefore to be limited only by the scope ofthe. appended claims.

I claim as my invention:

1. In a valve structure: means defining a chamber having an inlet and anoutlet; an inlet valve and an outlet valve controlling communicationbetween said inlet and said chamber and between the chamber and saidoutlet,` respectively, and comprising respectively, an inlet closuremovable into and out of engagement with an inlet valveseat and an outletclosure movable into and out of engage ment with an outlet valve seat;said chamber having a restricted passage connecting said outlet to saidchamber at a point intermediate said valves; means for actuating saidvalves sequentially in response to variations of a controlling conditionand comprising a member moved grad-` ually in opposite directions inresponse to variation of said condition in respective opposite senses; afirst lostmotion connection between said member and said outlet closure;and a second lost-motion connection between the member and said inletclosure; said lost-motion connections being arranged so that when saidcondition varies in a given sense the outlet closure is seated beforethe inlet closure is seated so that fluid can then pass to said outletonly by way of said restricted passage, and so that when the conditionsubsequently varies in the opposite sense the outlet closure is unseatedbefore the inlet closure is unseated so that fluid can pass relativelyunrestrictedly from the chamber to the outlet when the inlet closure issub sequently unseated.

2. A valve structure according to claim 1 and including means so biasingsaid first lost-motion connection that movement of said member relativeto said outlet closure is permitted only while the outlet closure is inengagement with its seat.

3. A valve structure according to claim l wherein said secondlost-motion connection comprises two-way snapaction means for moving theinlet closure abruptly into and out of seating position.

4. In a valve structure: a casing having an inlet and an outlet and,communicating respectively therewith, an inlet port and an outlet port;said casing having also a chamber interconnecting said ports, and arestricted passage connecting said outlet to said chamber at a pointintermediate the ports; means forming a valve seat around each of saidports; an inlet closure and an outlet closure mounted for movement intoand out of engagement with said inlet-port seat and said outlet-portseat, respectively, to control flow through the ports; means movable inresponse to Variation of a controlling condition for operating saidclosures sequentially and comprising a member moved gradually inopposite directions in response to variation of said condition inrespective opposite senses; a first connection between said member andsaid outlet closure, said first connection being yieldable and arrangedso that variation of said condition in a given sense effects seating ofthe outlet closure, so that fluid can then pass to said outlet only byway of said restricted pas sage, and subsequent movement of the memberrelative to the outlet closure while the outlet closure is seated; and asecond connection between the member and said inlet closure arranged sothat said subsequent movement of the member effects seating of the inletclosure, said second connection including means permitting limitedlost-motion between the member and the inlet closure such that when thecondition subsequently varies in an opposite sense the member can moverelative to the inlet closure and effect unseating of the outlet closurebefore the inlet closure is unseated, so that fluid can pass relativelyunre strictedly from the chamber to said outlet when the inlet closureis unseated.

5. A valve structure according to claim 4 wherein said second connectioncomprises two-way snap-action means for moving the inlet closureabruptly into and out of seating position.

6. In a valve structure: a valve casing having an elongatedgenerally-cylindrical chamber, and an inlet and an outlet communicatingwith respective opposite ends of the chamber; said casing having also arestricted passage connecting said outlet to said chamber intermediateits ends; means forming a valve-seat around each of said ends of thechamber; an inlet and an outlet closure mounted for movement into andout of engagement with the respective ones of said seats to control owthrough the casing; means movable in response to variation of acontrolling condition for operating said closures sequentially andcomprising a member moved gradually in opposite directions generallyalong the axis of the chamber in response to variation of said conditionin respective opposite senses, a portion of the member being inside thechamber; a iirst connection between said member and said outlet closure,said irst connection being yieldable and arranged so that variation ofsaid condition in a given sense effects seating of the outlet closureand subsequent movement of the member relative to the outlet closureWhile the same is seated; and a second connection between the member andsaid inlet closure arranged so that said subsequent movement of themember effects seating of the inlet closure, said second connectionincluding means permitting limited lost-motion between the member andthe inlet closure such that when the condition subsequently varies in anopposite sense the member can move relative to the inlet closure andeiect unseating of the outlet closure before the inlet closure isunseated.

7. A valve structure according to claim 6 wherein said second connectioncomprises two-way snap-action means for moving the inlet closureabruptly into and out of seating position.

8. A valve structure according to claim 6 wherein said member projectsthrough an opening in said outlet closure.

9. A valve structure according to claim 8 wherein said second connectionis inside said chamber,

10. A valve structure according to claim 6 wherein said seats face inopposite directions, and said second connection includes means foreecting movement of said inlet closure in directions opposite to thedirections of accompanying movement of said member.

ll. In a valve structure: a valve casing having an elongated cavitytherein; a pair of spaced-apart partitions dividing said cavitytransversely to form an inlet and an outlet compartment at opposite endsof the cavity, and a chamber between the partitions; said casing havingan inlet and an outlet communicating with the respective ones of saidcompartments, and a restricted passage connecting said outlet to saidchamber; each of said partitions having a port therethrough providedwith a valve seat, the one of said seats nearer said outlet compartmentfacing that compartment; an inlet closure and an outlet closure eachmounted for movement along the axis of the cavity into and out ofengagement with the respective ones of said seats to control flowthrough the casing, said outlet closure being located in said outletcompartment; means mounted on the casing and movable in response tovariation of a controlling condition for operating said closuressequentially, comprising a member moved gradually along the axis of thecavity in opposite directions in response to variation of said conditionin respective opposite senses, said member projecting through an openingin the-outlet closure and having portions within the outlet compartmentand the `chamber; a first lost-motion connection between said member andthe outlet closure and comprising a spring arranged to render theconnection rigid while the outlet closure is unseated and to yield whenthe outlet closure is seated so as to permit movement of said member ina direction inwardly of the chamber while said condition is varying in agiven sense; and a second lost-motion connection, inside the chamber,between the member and said inlet closure and arranged so that saidmovement of the member inwardly of the chamber effects seating of theinlet closure, said second lost-motion connection being arranged so thatwhen the condition subsequently varies in an opposite sense the membercan move relative to the inlet closure and effect unseating of theoutlet closure before the inlet closure is unseated.

12. A valve structure according to claim 11 wherein said secondlost-motion connection comprises two-way snap-action means for movingthe inlet closure abruptly into and out of seating position.

13. A valve structure according to claim 11 wherein the inlet one ofsaid seats faces said inlet compartment and said inlet closure is withinthe inlet compartment, and wherein said second lost-motion connectionincludes means for effecting movement of the inlet closure in directionsopposite to the directions of accompanying movement of said member.

References Cited n the ile of this patent UNITED STATES PATENTS2,253,866 Quoos Aug. 26, 1941 2,308,275 Gauger Jan. 12, 1943 2,608,349Landgrof et al. Aug. 26, 1952

